package study.reggie.filter;


import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;
import study.reggie.common.BaseContext;
import study.reggie.common.R;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/*
* 检查用户是否已经完成登录
* */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER=new AntPathMatcher();


    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest) servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;
        //1.获取本次请求的URI
        String requestURI=request.getRequestURI();

        log.info("拦截到请求:{}",requestURI);

        //定义不需要处理的请求路径
        String[] urls=new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",        //移动端发送短信
                "/user/login"           //移动端登陆
        };

        //2.判断本次请求是否需要处理
        boolean check=check(urls,requestURI);


        //3.如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4-1.判断登陆状态，如果已经登录，则直接放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("employee"));

            Long empId=(Long)request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            //发送http请求调用的方法都处于同一线程
            //ThreadLocal是Thread的局部变量，具有线程隔离的效果，只有该线程内才能获取到对应的值

            filterChain.doFilter(request,response);
            return;
        }

        //4-2.判断登陆状态，如果已经登录，则直接放行
        if(request.getSession().getAttribute("user")!=null){
            log.info("用户已登录，用户id为{}",request.getSession().getAttribute("user"));

            Long userId=(Long)request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            //发送http请求调用的方法都处于同一线程
            //ThreadLocal是Thread的局部变量，具有线程隔离的效果，只有该线程内才能获取到对应的值

            filterChain.doFilter(request,response);
            return;
        }

        //5.如果未登录则返回登陆界面，通过输出流方式向客户端响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /*路径匹配，检查本次请求是否需要放行*/
    public boolean check(String[]urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
